diff options
| author | Max Filippov <jcmvbkbc@gmail.com> | 2016-09-20 20:11:08 +0200 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2016-09-21 03:52:59 +0200 |
| commit | 205ad548a7426fb6813760cd9917d3fc24122576 (patch) | |
| tree | afee669f50dad5b75f622cecc03074d12c9b8e5f /arch/xtensa/kernel | |
| parent | xtensa: xtfpga: use clock provider, don't update DT (diff) | |
| download | linux-205ad548a7426fb6813760cd9917d3fc24122576.tar.xz linux-205ad548a7426fb6813760cd9917d3fc24122576.zip | |
xtensa: rearrange CCOUNT calibration
DT-enabled kernel should have a CPU node connected to a clock. This clock
is the CCOUNT clock. Use old platform_calibrate_ccount call as a fallback
when CPU node cannot be found or has no clock and in non-DT-enabled
configurations.
Drop no longer needed code that updates CPU clock-frequency property in
the DT; drop DT-related code from the platform_calibrate_ccount too.
Move of_clk_init to the top of time_init, so that clocks are initialized
before CCOUNT calibration is attempted.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/kernel')
| -rw-r--r-- | arch/xtensa/kernel/setup.c | 2 | ||||
| -rw-r--r-- | arch/xtensa/kernel/time.c | 40 |
2 files changed, 39 insertions, 3 deletions
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c index 7ed63688f93c..d61c8468abea 100644 --- a/arch/xtensa/kernel/setup.c +++ b/arch/xtensa/kernel/setup.c @@ -23,7 +23,6 @@ #include <linux/bootmem.h> #include <linux/kernel.h> #include <linux/percpu.h> -#include <linux/clk-provider.h> #include <linux/cpu.h> #include <linux/of.h> #include <linux/of_fdt.h> @@ -249,7 +248,6 @@ void __init early_init_devtree(void *params) static int __init xtensa_device_probe(void) { - of_clk_init(NULL); of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); return 0; } diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c index b9ad9feadc2d..9a5bcd0381a7 100644 --- a/arch/xtensa/kernel/time.c +++ b/arch/xtensa/kernel/time.c @@ -12,6 +12,8 @@ * Chris Zankel <chris@zankel.net> */ +#include <linux/clk.h> +#include <linux/clk-provider.h> #include <linux/errno.h> #include <linux/sched.h> #include <linux/time.h> @@ -134,16 +136,52 @@ void local_timer_setup(unsigned cpu) 0xf, 0xffffffff); } +#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT +#ifdef CONFIG_OF +static void __init calibrate_ccount(void) +{ + struct device_node *cpu; + struct clk *clk; + + cpu = of_find_compatible_node(NULL, NULL, "cdns,xtensa-cpu"); + if (cpu) { + clk = of_clk_get(cpu, 0); + if (!IS_ERR(clk)) { + ccount_freq = clk_get_rate(clk); + return; + } else { + pr_warn("%s: CPU input clock not found\n", + __func__); + } + } else { + pr_warn("%s: CPU node not found in the device tree\n", + __func__); + } + + platform_calibrate_ccount(); +} +#else +static inline void calibrate_ccount(void) +{ + platform_calibrate_ccount(); +} +#endif +#endif + void __init time_init(void) { + of_clk_init(NULL); #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT printk("Calibrating CPU frequency "); - platform_calibrate_ccount(); + calibrate_ccount(); printk("%d.%02d MHz\n", (int)ccount_freq/1000000, (int)(ccount_freq/10000)%100); #else ccount_freq = CONFIG_XTENSA_CPU_CLOCK*1000000UL; #endif + WARN(!ccount_freq, + "%s: CPU clock frequency is not set up correctly\n", + __func__); clocksource_register_hz(&ccount_clocksource, ccount_freq); local_timer_setup(0); setup_irq(this_cpu_ptr(&ccount_timer)->evt.irq, &timer_irqaction); |